As is well known, diseases of trees are not unusual and a particularly devastating disease is Dutch Elm Disease. In an effort to aid in the treatment and inhibit the growth of Dutch Elm Disease, it has been common to treat the trees with fungicides such as benomyl fungicide sold under the trademark "BENLATE"by E. I. Du Pont De Nemours Co. Such a fungicide is suspended in water and usually injected into the trees. Another fungicide under experimental use at the present time is Fungicide BLP having the active ingredients of methyl 2-benzimidazolecarbamate phosphate. The latter fungicide is corrosive as are most soluble fungicides.
In one type of system for applying fungicides, holes are drilled circumferentially around the trees and nozzles are inserted into the holes. Adjacent nozzles are interconnected by tubing, each segment of which is captive to is nozzle by design and fabrication, and the liquid containing the fungicide is connected to the tubing from a single pressure tank which is usually a manual pressurized tank. In another system, a plurality of tubes are extended to each nozzle from a manifold and the liquid is supplied to the manifold under pressure from a single tank.
One of the problems in such treatments is the control of the amount of liquid supplied to each tree. It has been common to utilize a tank of a particular size and apply the entire contents of the tank or apply the liquid to the tree for a predetermined period of time, whichever occurs first. Since the fluid pressure applied to the liquid may fluctuate, there is no assurance of the correct amount nor that adequate pressure was available to lift the mixture to the furthest parts of the crown. Moreover, if more is needed than is available in a single tank, it is necessary to stop the operation for a sufficient length of time to refill the tank.
Accordingly, among the objects of the invention are to provide a system wherein the amount of the liquid may be varied, the use of small tanks is permitted, and the treatment is not interrupted for any substantial length of time in order to refill the tanks. This is important since in the case of wettable powder application, this system's higher average pressure capability tends to insure completion of injection before material precipitates out of suspension.
Another problem with respect to such prior systems is that different nozzles are utilized at different points around the tree so that care must be exercised in placement of the nozzles and a supply of different parts is needed. Accordingly, among the objects of the invention is to provide a system utilizing interchangeable parts so that relatively unskilled labor may be used in applying the equipment to the tree while permitting the licensed applicator to select the most critical point in the circumference of the tree for prime (top pressure) placement.
Another problem with respect to the prior systems is that when a line is plugged as by failure of passage through any particular nozzle or air entrapment, it is difficult to determine such stoppage readily. Accordingly, among the objects of the invention is to provide a system wherein stoppage or leakage may be readily detected and immediately bridged, allowing injection to continue while repair is underway.
A further object of the invention is to provide a system wherein clumps of trees can be treated readily and wherein the time of treatment may be controlled both from the standpoint of proper treatment of the tree and savings in time of usage of the equipment and labor.
Another object of the invention is to provide a completely closed system, wherein no one, other than the licensed applicator, has contact with the injectable material.